Inline muffler and positive airway pressure therapy apparatus including same

Abstract

An inline muffler for use with a positive airway pressure (PAP) apparatus. The muffler may provide an expansion chamber with baffles that capture acoustic energy using, for instance, a disruptive gas flow path to effectively reduce downstream noise associated with a flow of pressurized gas produced by the PAP apparatus. In some embodiments, the muffler is constructed of two mostly identical halves with baffle segments being integrally formed therewith.

What is claimed is: 
     
         1 . A positive airway pressure apparatus comprising:
 a flow generator comprising a housing containing a blower, the blower adapted to produce a flow of pressurized gas at a blower outlet;   a user interface;   an elongate delivery tube positioned between the flow generator and the user interface, the delivery tube adapted to communicate the flow of pressurized gas from the blower to the user interface; and   an inline muffler positioned between the blower and the delivery tube, wherein the muffler comprises a tubular member adapted to attenuate noise associated with the flow of pressurized gas as the gas passes through the muffler, the muffler comprising:
 an inlet port adapted to operatively couple to the blower outlet; 
 an outlet port adapted to operatively couple to a proximal end of the delivery tube, wherein the inlet port and the outlet port define a muffler axis; and 
 a body extending between the inlet port and the outlet port, wherein the body defines an expansion chamber having an effective inner diameter larger than an effective inner diameter of both the inlet port and the outlet port, and wherein an inner wall of the body comprises a plurality of inwardly extending baffles, the baffles adapted to capture sound energy associated with the flow of pressurized gas passing through the expansion chamber, and wherein one or more of the baffles comprises two intersecting planar baffle segments defining a chevron. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the baffles are integrally formed with the body of the muffler. 
     
     
         3 . The apparatus of  claim 1 , wherein the capture of the sound energy comprises one or more of: destructive interference of sound energy; diffusion of sound energy; attenuation of sound energy; suppression of sound energy; absorption of sound energy; and redirection of sound energy. 
     
     
         4 . The apparatus of  claim 1 , wherein the two intersecting planar baffle segments intersect one another along a line that intersects the muffler axis. 
     
     
         5 . The apparatus of  claim 1 , wherein the planar baffle segments are integrally formed with the inner wall. 
     
     
         6 . The apparatus of  claim 1 , wherein the muffler comprises two halves secured to one another. 
     
     
         7 . The apparatus of  claim 6 , wherein each of the two halves are produced through an injection molding process. 
     
     
         8 . The apparatus of  claim 6 , wherein the two halves are secured to one another via one of ultrasonic welding, bonding, snap-fit engagement, fastening, and overmolding. 
     
     
         9 . The apparatus of  claim 1 , wherein the baffles comprise an impermeable material. 
     
     
         10 . The apparatus of  claim 9 , wherein the baffles comprise a plastic material. 
     
     
         11 . An inline muffler adapted to be positioned within a gas delivery path of a positive airway pressure apparatus between a blower and a user interface, the muffler comprising a tubular housing defined by first and second halves secured to one another, wherein the housing comprises:
 a first end defining an inlet port;   a second end defining an outlet port; and   a body extending between the first end and the second end, the body defining an expansion chamber between the first and second ends of the housing, wherein a plurality of baffles extends between opposing inner walls of the expansion chamber, and wherein at least one of the plurality of baffles is formed by a first baffle segment integrally formed with the first half that aligns with a second baffle segment integrally formed with the second half, the two baffle segments comprising distal portions that terminate at or near one another within the expansion chamber.   
     
     
         12 . The muffler of  claim 11 , wherein the plurality of baffles is adapted to capture sound energy associated with a flow of pressurized gas passing from the inlet port to the outlet port. 
     
     
         13 . The muffler of  claim 11 , wherein one or more of the plurality of baffles comprises a shape selected from one or both of planar baffle segments and curved baffle segments. 
     
     
         14 . The muffler of  claim 11 , wherein the first and second baffle segments form a chevron when viewed normal to a mating plane of the first and second halves. 
     
     
         15 . The muffler of  claim 11 , wherein one or more of the plurality of baffles defines an aperture. 
     
     
         16 . The muffler of  claim 11 , wherein the first and second halves are secured to one another via one of comprising ultrasonic welding, bonding, snap-fit engagement, fastening, and overmolding. 
     
     
         17 . The muffler of  claim 11 , further comprising a compressible seal positioned between the first and second halves. 
     
     
         18 . The muffler of  claim 11 , wherein the first and second halves each comprise an impermeable material. 
     
     
         19 . The muffler of  claim 11 , wherein the first and second halves each comprise a plastic material. 
     
     
         20 . An inline muffler adapted to be positioned within a gas delivery path of a positive airway pressure apparatus between a blower and a user interface, the muffler comprising:
 a tubular housing, the housing comprising:
 an inlet port adapted to operatively couple to an outlet of the blower; 
 an outlet port adapted to operatively couple to a proximal end of a delivery tube that fluidly communicates with the user interface; and 
 a body extending between the inlet port and the outlet port, wherein the body defines an expansion chamber having an effective inner diameter larger than an effective inner diameter of both the inlet port and the outlet port, and wherein an inner wall of the body comprises a plurality of inwardly extending baffles, the baffles adapted to capture sound energy associated with a flow of pressurized gas passing through the expansion chamber, and wherein at least one of the baffles comprises first and second baffle segments that define a chevron having an apex centered on a muffler axis defined by the inlet port and the outlet port. 
   
     
     
         21 . A positive airway pressure apparatus comprising:
 a flow generator comprising a housing containing a blower, the blower adapted to produce a flow of pressurized gas at a blower outlet;   a user interface;   an elongate delivery tube positioned between the flow generator and the user interface, the delivery tube adapted to communicate the flow of pressurized gas from the blower to the user interface; and   an inline muffler positioned between the blower and the delivery tube, wherein the muffler comprises a tubular member adapted to attenuate noise associated with the flow of pressurized gas as the gas passes through the muffler, the muffler comprising:
 an inlet port adapted to operatively couple to the blower outlet; 
 an outlet port adapted to operatively couple to a proximal end of the delivery tube; and 
 a body extending between the inlet port and the outlet port, wherein the body defines an expansion chamber having an effective inner diameter larger than an effective inner diameter of both the inlet port and the outlet port, and wherein an inner wall of the body comprises a plurality of inwardly extending baffles, the baffles adapted to capture sound energy associated with the flow of pressurized gas passing through the expansion chamber, wherein the muffler comprises two halves secured to one another.